I have seen questions raised about the correct name for the symbol @ many times, often suggesting that it has no name:

Email, with its address template addressee@server.com, is virtually universal. Nevertheless, the @ that unequivocally marks it as an email address has no generally accepted English name. (Julian Burnside)

Names such as 'atmark' and 'commercial at' are also suggested, though these are not very common; Google gives 14,200 and 35,600 results respectively. However, given that I've never heard @ called anything other than at, I can't see why this can't be considered to be its correct name, just like the names of letters. When it was only used in certain bills, the debate may have been valid, but now that it's a universal symbol, I fail to see the need for it to have a 'proper' name.